package chap03;

public class interface_test {
}

interface Calculate {
    final float PI = 3.141592f;

    float getArea(float t);

    float getCircumference(float r);
}

 class Cire implements Calculate {
    public float getArea(float r) {
        float area = PI * r * r;
        return area;
    }

    public float getCircumference(float r) {
        float Circumference = PI * r * r * 2;
        return Circumference;
    }
}
//第二段内容 以
interface Animal{
    public abstract void work();
    public abstract void bird();
}
 interface BurnAnimal extends Animal{
    //interface  inherit it
}
